Device for checking the rebound from impact in reciprocating apparatus.



No. 65l,320. Patented June 5, I900.

c. B. ALB BEE.

DEVICE FOR CHECKING THE REBOUND FROM IMPACT IN REGIPROGATING APPARATUS.

(Application filed Jan. 25, 1900.)

(No Model.)

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CHESTER l3. ALBREE, ALLEGHENY, PENNSYLVANIA. I

DEVICE FOR CHECKING THE REBOUND FROM IMPACT lN REClPROCATlNG APPARATUS.

SPECIFICATION forming part of Letters Patent No 6515320, dated Julie1906:

Application filed January 25, 1900. Serial No- 2,724. (No model.)

To aZZ whom it may concern.-

Be it known that I, CHESTER B. ALB'REE, of Allegheny, in the county ofAllegheny and State of Pennsylvania, have invented a new and usefulImprovemen t in Devices for Checking the Rebound from Impact inReciprocating Apparatus, of which the following is a full, clear, andexact description, reference being had to the accompanying drawings,forming part of this specification, in which Figure 1 is a verticallongitudinal sectional view of my improved device as applied to thereciprocating part of a pneumatic or steam tool. Fig. 2 is an enlargeddetail view of the same. Fig. Sis aside elevation, broken away andpartially in section, of a drop-press to which my device is applied.Figs. 4 and 5 are detail views at different points of operation of thesame, and Fig. 6 is a modification as applied to another form ofapparatus.

My invention relates, primarily, to the reciprocating part of apparatusof the poroussive or hammer type, and is designed to afford a means forpreventing or greatly overcoming the rebound of said reciprocating partincident to its impact.

To this end it consists, broadly, in a rider or riders adapted to movewith reciprocating part and by impact to absorb or neutralize therebound thereof.

Referring more particularly to Figs. 1 and 2, in which I show my deviceas. applied to the tool-motor shown and describedin my PatentNo.638,490,and it may be applied similarly to the motor of my Patent No.638,489, 2 represents the cylinder, having a cylinderhead 3 and a pistonof two diameters 4 4, which at its end has a 'socketT, designed toreceive the tool or other instrument which it is used for operating. 5is the inlet-port,connected with a source of compressed air or othermotive fluid. The piston has, a hollow passage 6 extending through it,preferably cylindrical in form, and'in that passage is a valve 7 ,whichfits neatly therein, but can slide back and forth, as hereinafterexplained. 8 8 are exhaust-portsleading from the hollow piston, asshown. The valve 7 is formed with openings constituting ports 10,adapted to register with the exhaust-ports 8 when the valve is in theposition shown in Fig. 1, and with ports 11, adapted to register withthe and 8 to the atmosphere.

ports 9 when the valve is in its reverse posi tion. 12 is a stop at theend of the hollow passage of the piston, adapted to limit the backmotion of the sliding valve. Within the valve 7, preferably at its innerend, I place a tubular rider 13. This rider is loose in the sense thatit is capable of independent motion, and for this purpose it is adaptedto slide back and forth. I provide the passage 7 with an enlargedportion 14, said portion 14 having a stop 15 and stop-washers 16 16. Thewashers, however, are not essential, being provided merely to afiord acushion for the rider 13.

The operation is as follows: The parts being in the position shown inFig. 1, motive fluid is admitted through the port 5 and, en-

tering the cylinder at the smaller diameter of the piston, forces thepiston back to the rear end of the cylinder, the air which is back ofthe piston being displaced throughthe passage 6, hollow valve 7, andexhaust-port's 10 When the piston reaches the end of its back stroke andis stopped by engagement with the head 3, the valve 7 is caused by itsinertia to move back into contact with the stop 12, and at the same timethe rider 13 is caused to move back into contact with the stop 15, thevalve 7 then closing the exhaust-port 8 and putting the ports 9 intocommunication with the interior of the hollow valve by way of the ports11, which then register therewith. Thereupon the air passes through theports 9 11, valve 7,-and passage 6 to the cylinder back of the piston,thus tending to equalize the pressure therein with the pressure at theother end of'the piston, and by reason of the differentialarea thepiston is forced forward. When it reaches the end of its outstroke or iffor any reason, as is very common in tools of this class,- its motionshould be checked by coming in contact with some obstacle before the endof its normal out-stroke is reached, the

a valve 7 is caused by inertia to move forward into the position shownin Fig. 1, and there non-registration of the ports of valve 7 after eachimpact both forward and rearward due to the elasticity of the valve andpiston. To obviate this is one ofthe objects of the present inventionand is accomplished by the rider 13 as follows: When the piston, withits contained valve, has moved to its rearward position, the rider 13will also assume its extreme rearward position, as shown by dotted linesin Fig. 2, and by reason of its inertia it will maintain a rearward orlagging position during the outward movement of the piston. The instantthat the outward movement of the piston is arrested the valve 7 willmove forward, as hereinbefore described, to perform its function ofaltering the flow of air. The instant that the movement of the valve 7is arrested the rider 13 will move forward by reason of its inertia and,contacting with the forward shoulder 6,will neutralize the reboundingimpetus of the valve. The rider 13 and valve 7 are then in positionrelative to the piston to repeat the above-described operation at itsreturn inward stroke. It will be understood that the movements abovedescribed are very rapid. The piston in ordinary use may reciprocateapproximately one thousand times a minute, so that the moment ofstoppage of the rider is practically simultaneous with the moment ofstoppage of the valve 7. It is obvious that the shape and position ofthe rider with respect to the valve are unimportant, so long as they donot interfere with the functions of the valve.

Referring now to Figs. 3, l, and 5, in which I show my device as appliedto a steam drop press or hammer, 17 is the frame or standards, havingsuitable guides 18, in which reciprocates a head 19, to which power istransmitted by a piston-rod 20 from a suitable cylinder. (Not shown.) 21and 22 are upper and lower dies, respectively, of any desirable shape.The piston-rod 20 is provided with collar 23, adapted to confine thevertical movement of the rider 21 thereon, as shown.

The press or hammer is operated in the usual manner, and my improveddevice acts as follows: The rider 24 by reason of gravity will normallyrest upon the head 19, as shown in Figs. 3 and 5, Fig. 3 showing theposition of the parts at rest before the operation of the press orhammer and Fig. 5 showing the position of the parts at rest at the endof a single stroke; but during the descent of head 19, because its speedis greater than the attraction of gravity, said rider 24 will tend tolag behind until caught by the collar 23, when it will descend with thesame speed as the head 19, the relative position of the parts midway intheir descent being as shown in Fig. 4, and this relative position ismaintained until the limit of descent is reached and the movement of thehead 19 is arrested. The descent of the rider 24, however, is notarrested until it completes the extent of its movement and strikes thehead 19. As stated with reference to Figs. 1 and 2, the movements hereindescribed are rapid, so that the interval be tween the moment of impactof die 21 upon die 22 and the moment of impact of rider 24 upon head 19is small.

Referring now to Fig. 6, I show in conventional form a pile-driver ofthe gravity type, in which I illustrate my device'when bothreciprocating part and its rider are actuated by gravity. 25 is thereciprocating part or hammer, movable in vertical guides 20 and havingpin 27 and head 28 integral therewith. 29 is the rider, confined looselyon the pin 27 by the head 28, to which is secured an actuating-rope 30.

The operation of the apparatus shown in Fig. 6 is similar to that shownin Fig. 3. It will be observed, however, that whereas in the latter casethe rider lags by reason of the difference in velocity in Fig. 6 therider is caused to lag by the suspending rope.

The effectof the action above described will be readily understood. Uponimpact of reciprocating parts a portion of the direct force exertedthereby is converted into reflex or rebounding motion, which isimmediately absorbed and neutralized by the inertial force exerted bythe rider, the said rider being con structed of weight adaptedto itsindividual condition. I have discovered that the rebound of steel uponsteel is approximately three-tenths of the direct force exerted, andtherefore under such conditions I provide a rider of about three-tenthsthe weight of the reciprocating part.

The advantages of my invention will be 'appreciated by those skilled inthe art to which it relates, since it affords eifective means forovercoming the rebound hereinbefore 1nentioned. The disadvantagesarising from this rebounding in pneumatic tools have been hereinbeforeexplained, and the disadvantages in the art of press and die works arealso well marked. In the latter case many expedients have been attemptedto overcome the difficulty, notably the skilful manipulation of theactuating fluid, whereby the re ciprocating part is caught on itsrebound; but such manipulation necessitates the employ ment ofwell-trained and especially-skilled workmen. By the use of my inventionthis difiiculty is overcome and ordinary unskilled labor may beemployed.

Many changes may be made in the form,- material, and application of mydevice without departure from my invention as defined in the claims. Therider may be modified in form, position, and size to meet therequirements of individual cases, and, although I ordinarily constructthe same of steel or iron,- I have found that hard fiber, wood, oranalogous material may be used. Other changes will suggest themselves tothe skilled mechanic within the scope of my invention.

I claim-- 1. A device for checking rebound in reciprocating mechanism,comprising, in combina= tion with a bodyhaving atendencyto rebound,

a body arranged to move with the reciprocating part and impact therewithat the limit of its reciprocatory movement; substantially as described.

2. A device for checking rebound in reciprocating mechanism, comprising,in combinationwithabody havingatendency to rebound, a loose and laggingbody arranged to move with the reciprocating part and by its inertiacheck rebound; substantially as described.

3. In tool-motors having a reciprocating valve, a body loosely carriedwith said valve and arranged to impact therewith at'the limit of itsreciprocating movement; substantially as described.

4. In toolmotors having a reciprocating piston and valve, a tubularrebound-checking rider loosely carried by said valve and arrangedto.impact therewith at the limit of its movement; substantially asdescribed.

5. In tool-motors having a reciprocating piston, a tubular inertia-valvecarried therein, and a tubular rebound-checking rider carried within thevalve; substantially as described.

6. In tool-motors having a reciprocating piston and valve, a bodyarranged to reciprocate within said valve and impact therewith at thelimit of each reciprocating movement thereof; substantially asdescribed.

In testimony whereof I have hereunto set my hand.

CHESTER B. ALBREE.

Witnesses:

G. I. HOLDSHIP,

H. M. OORWIN.

